package matching

import (
	"context"
	"testing"

	"github.com/shopspring/decimal"

	"github.com/missionworkforce/missionmatch/internal/modules/matching/engine"
)

type stubEmbedder struct{ vecs map[string][]float32 }

func (s stubEmbedder) Embed(_ context.Context, t string) ([]float32, error) {
	if v, ok := s.vecs[t]; ok {
		return v, nil
	}
	return []float32{0, 0}, nil
}
func (s stubEmbedder) EmbedBatch(ctx context.Context, ts []string) ([][]float32, error) {
	out := make([][]float32, len(ts))
	for i, t := range ts {
		out[i], _ = s.Embed(ctx, t)
	}
	return out, nil
}
func (s stubEmbedder) Dimension() int { return 2 }

func TestEmbeddingSkillMatcher(t *testing.T) {
	// Unit vectors: cosine("Amazon EKS","Kubernetes")=0.9 ; cosine with "Java"=0.
	emb := stubEmbedder{vecs: map[string][]float32{
		"Amazon EKS": {1, 0},
		"Kubernetes": {0.9, 0.43589}, // |v| ~= 1
		"Java":       {0, 1},
	}}
	m := NewEmbeddingSkillMatcher(emb)
	req := engine.RequiredSkill{SkillID: "eks", Name: "Amazon EKS"}
	cands := []engine.CandidateSkill{{SkillID: "k8s", Name: "Kubernetes"}, {SkillID: "java", Name: "Java"}}

	got, ok := m.Match(context.Background(), req, cands, decimal.RequireFromString("0.80"))
	if !ok || got.CandidateName != "Kubernetes" || got.CandidateSkillID != "k8s" {
		t.Fatalf("threshold 0.80 should match Kubernetes, got %+v ok=%v", got, ok)
	}
	if got.Similarity.LessThan(decimal.RequireFromString("0.89")) {
		t.Fatalf("similarity should be ~0.9, got %s", got.Similarity)
	}

	if _, ok := m.Match(context.Background(), req, cands, decimal.RequireFromString("0.95")); ok {
		t.Fatal("threshold 0.95 must reject a 0.9 similarity")
	}
	if _, ok := m.Match(context.Background(), req, nil, decimal.RequireFromString("0.50")); ok {
		t.Fatal("no candidate skills must yield no match")
	}
}